Created attachment 189179 [details]
WAYLAND=on build overrides the list of enabled platforms. Since Mesa 17.2.0 surfaceless platform was enabled by default upstream but WAYLAND option hasn't been adjusted. Notice -DHAVE_SURFACELESS_PLATFORM in build logs which disappears if WAYLAND option is enabled.
The regression affects both WAYLAND=on and WAYLAND=off. I guess, the latter is to avoid accidentally picking up libwayland* as a dependency.
A commit references this bug:
Date: Tue Oct 16 00:00:09 UTC 2018
New revision: 482191
graphics/mesa-libs: enable surfaceless like upstream
Approved by: maintainer timeout (9 months)